Set a 6-quart Instant Pot to saute; add olive oil and butter.
In a small bowl, stir together salt, pepper, brown sugar, and smoked paprika.
Sprinkle pork tenderloin evenly with salt mixture.
When oil mixture is hot, add pork to Instant Pot. Cook until browned on both sides, about 3 minutes per side. Remove pork; set aside.
Add onion and apple to Instant Pot; saute 4 minutes, stirring occasionally.
Add bourbon and vinegar to Instant Pot; stir to release browned bits.
Press Cancel to reset Instant Pot. Return pork to Instant Pot.
Place top on Instant Pot; twist to seal and lock. Turn Steam Release Valve to “sealing.”
Set Instant Pot to cook at High Pressure for 7 minutes.
After cooking is complete, let pressure release naturally (approximately 10 minutes). After
that, manually release the pressure by turning the Steam Release Valve to “venting.”
Remove pork from Instant Pot. Press Cancel to reset Instant Pot; stir in molasses.
Saute apple mixture until slightly thickened, stirring occasionally, about 5 minutes.
Spoon apple mixture onto a platter; top with arugula and sliced pork.
Drizzle with any remaining juices.